This medlegal case involved a patient who was undergoing an open heart surgery procedure.  While preparing to put the patient on a heart lung bypass machine to oxygenate the patient’s blood, the aortic cannula was placed facing the wrong direction and the cross clamp was placed across the cannula.  This lead to massive blood loss back through the aorta into the heart.

The first objective was to explain normal blood flow through the heart. This would show the abnormal (backward) blood flow through the aortic valve.


When a heart lung bypass is placed according to the standard of care, the aortic cross clamp allows blood to flow to the body while keeping the aortic valve clear of blood to allow other procedures to be performed on the heart.


In this case it was known that the cannula was placed facing towards the heart, causing blood to flow through or around the cross clamp and to the aortic valve.


It was also possible that the cross clamp was not placed across the cannula, but allowed the cannula tip to pass along side of the aorta. This scenario would also allow blood to flow toward the aortic valve.


The final panel was created to compare the standard of care with what actually happened during this procedure.